• 대한환경공학회지
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• 제36권9호
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• pp.609-613
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• 2014

본 연구는 미세조류 생장에 중요한 영향인자인 N/P ratio가 미세조류의 생장과 하수의 영양염류 제거에 미치는 영향을 알아보고자 하였다. 실험을 위하여 1-70까지의 다양한 N/P ratio를 준비하였으며, 미세조류는 Botryococcus braunii를 사용하였다. 실험결과 바이오매스 생산을 위하여 필요한 N/P ratio는 5-30이었다. TN의 제거율은 N/P ratio 1-30까지는 82%, 31-70까지는 73-78%의 제거율을 나타내어 TN 제거를 위한 N/P ratio는 1-30까지가 가장 좋았다. TP의 제거율 N/P ratio 1-20까지는 80% 이상의 높은 제거율을 나타내었지만, 20 이상부터는 급격하게 하락하여 50 이상에서는 22% 정도의 제거율로 변화가 없이 일정하였다. 따라서 바이오매스 생산량과 하수에서의 TN, TP의 제거를 위한 N/P ratio는 1-30이 가장 좋은 비율로 나타났다. TN, TP 제거율과 바이오매스의 생산량 상관관계는 TP 제거율과 바이오매스 생산량의 상관계수가($R^2$) 0.9126으로 상관관계가 매우 높았으나, TN 제거율과 바이오매스 생산량과의 상관관계는 찾을 수가 없었다. 이는 하수에서 TP의 함량이 TN의 함량보다 바이오매스 생산량에 밀접한 관계가 있음을 알 수 있다.

• 한국작물학회지
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• 제39권5호
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• pp.480-488
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• 1994

White clover는 기존초지에 도입시 정착이 불량한 것이 단점으로 지적되어 왔다. 본시험은 white clover의 발아직후 자엽 및 단엽제거가 건물생산과 형태적 특성에 미치는 영향을 조사하여 기존초지로 도입되는 white clover의 유묘기 관리에 관한 정보를 제공하고자 잎의 크기가 다른 4개 품종(Regal, La. S-1, Huia, S184)을 자엽기에 1개 또는 2개의 자엽을 제거하거나, 단엽기에 단엽, 단엽과 1개의 자엽 또는 단엽과 2개의 자엽을 모두 제거한 후 8주동안 개체당 건물중과 형태적 형질(엽수, 엽면적, 엽병장, 포복경장 및 분지경수)의 변화와 개체당 건물중과 이들 형질과의 관계를 밝히고자 실시하였던 바, 그 결과를 요약하면 다음과 같다. 1. 무탈엽에 비하여 자엽 및 단엽제거는 clover의 개체당 건물중과 형태적 형질을 현저히 감소시켰다. 2. 건물중과 형태적 형질은 단엽기에 단엽과 자엽 제거에 의하여 더욱 감소되고 자엽제거가 많을수록 감소가 큰 것으로 나타났다. 3. 자엽 및 단엽제거 후 생장기간이 증가함으로써 건물중과 형태적 형질이 증가한다 할지라도 포복경장과 분지경수는 처리 6주후부터 급격히 증가하였다. 4. 건물중, 엽면적 및 엽병장은 대엽종일수록 크나, 포복경장, 분지경수 및 엽수는 소엽종일수록 큰 경향을 보였다. 5. 건물중 증가는 엽면적 증가와 밀접한 관련이 있었으나 자엽기에 자엽제거가 단엽기에 단엽과 자엽제거, 그리고 탈엽이 심할수록 증가율(기울기)감소가 큰 것으로 분석되었다.

• 대한환경공학회지
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• 제22권12호
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• pp.2163-2173
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• 2000

메탄자화균에 의한 코발트 제거의 최적 pH 영역은 6.0~12.0이었으나 메탄자화균을 넣지 않은 blank는 10.5~11.5이었다. 코발트의 제거능은 pH에 크게 의존하였으나 blank보다는 민감하지 않았다. 초기 pH 6.0에서 1.0 g/L의 메탄자화균을 투입했을 때 170 mg Co/g biomass가 제거되었다. SEM 분석 결과에 의하면 코발트는 메탄자확균의 표면이나 세포의 분비 고분자에 흡착되어 제거된 것으로 사료된다. 초기 pH 6.0, 400 mg Co/L에서 메탄자화균의 최적의 투입량은 1.0 g/L이었다. 2.0 M NaCl과 $NaNO_3$의 높은 이온강도 하에서도 코발트 제거능은 그다지 영향을 받지 않았다.

• Journal of Microbiology and Biotechnology
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• 제29권9호
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• pp.1434-1443
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• 2019

Although chemical oxygen demand (COD) is an important issue for wastewater treatment, COD reduction with microalgae has been less studied compared to nitrogen or phosphorus removal. COD removal is not efficient in conventional wastewater treatment using microalgae, because the algae release organic compounds, thereby finally increasing the COD level. This study focused on enhancing COD removal and meeting the effluent standard for discharge by optimizing sludge inoculation timing, which was an important factor in forming a desirable algae/bacteria consortium for more efficient COD removal and higher biomass productivity. Activated sludge has been added to reduce COD in many studies, but its inoculation was done at the start of cultivation. However, when the sludge was added after 3 days of cultivation, at which point the COD concentration started to increase again, the algal growth and biomass productivity were higher than those of the initial sludge inoculation and control (without sludge). Algal and bacterial cell numbers measured by qPCR were also higher with sludge inoculation at 3 days later. In a semi-continuous cultivation system, a hydraulic retention time of 5 days with sludge inoculation resulted in the highest biomass productivity and N/P removal. This study achieved a further improved COD removal than the conventional microalgal wastewater treatment, by introducing bacteria in activated sludge at optimized timing.

• 상하수도학회지
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• 제14권1호
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• pp.62-75
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• 2000

Most of biological treatment to remove contaminants in municipal wastewater have been conducted by activated sludge process. But, the process have several probIems such as enormous site needed for construction of treatment facilities, unstable treatment due to limited ability to control load fluctuation, frequent sludge bulking and appearance of lots of surplus sludge. In this study, the experiments were performed through submerging biofilm of PEPP media in existing aeration tank with raw water from municipal wastewater treatment plant and then submerging PVDC and PEPP media, different from shape and chemical peculiarity in anoxic reactor. Throughout the experience, nutrient removal efficiency according to HRT, nitrogen phosphorous removal efficiency, behavior of nitrogen and dewatering efficiency have been compared and analysed with those of activated sludge process. As the results, BOD removal efficiency according to BOD volumetric load and F/M ratio was not found any differency in two processes, but was decreased below 90% as going along the condition of high load in activated sludge process. Kinetic coefficient was $K_{max}=1.162day^{-1}$, $K_s=53.77mg/L$, $Y=0.166mgVSS/mgBOD_{rem}$. and $K_d=0.019day^{-1}$. It was found that the removal efficiency, even though in aerobic condition, in biofilm process equipped anoxic reactor was higher than the one in activated sludge process within the range of 70~80%, and became better as HRT increased. Phosphorous removal efficiency was not found any differency in two processes. In biofilm process, treament efficiency even in conditions of high load was not decreased, because the biomass concentration could be maintained in high condition compared with activated sludge process. As HRT increased, suspended and attached biomass was increased and the other hand, F/M ratio was decreased as biomass' increasing. Biomass thickness was increased. from $10.43{\mu}m$ to $10.55{\mu}m$ as HRT increased and density of biomass within $40.79{\sim}41.16mg/cm^2$. The results also present that the dewatering efficiency of sludge generated in biofilm process was higher than in activated sludge process, and became better as HRT increased.

• KSBB Journal
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• 제6권4호
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• pp.345-350
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• 1991

본 연구에서는 생물막 유동층 반응기를 이용하여 주정공장폐수를 처리함에 있어 상향유속과 유기물 부하의 변동에 따른 미생물의 성상과 유기물 처리효율을 조사하고, 미생물 성장과 유기물 처리효율을 조사하고, 미생물 성상에 따른 미생물 농도의 변화를 계산하여 이를 실측한 미생물 농도와 비교하였다. 상향유속에 따라 미생물 농도, 미생물막 두께는 민감한 반응을 보였고, 미생물 농도를 높게 유지하기 위해서는 상향유속을 낮게 유지하는 것이 효과적이나, 이에 따라 미생물막도 증가하나 유기물의 제거율은 상대적으로 증가하지 못하므로 적절한 상향유속을 유지하는 것이 유기물 제거율이 측면에서는 유리한 것으로 고찰되었다. 또한 기존 활성슬러지법에서 주정폐수를 처리할 때는 유기물 부하율 1.5kgCOD/$m^3{\cdot}day$에서 70% 이하의 COD처리효율을 나타내는데 반해, 생물막 유동층 반응기에서는 6kgCOD/$m^2{\cdot}day$ 이상에서도 80%의 COD처리효율을 나타내었다.

• Journal of Microbiology and Biotechnology
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• 제16권11호
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• pp.1720-1727
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• 2006

To set up a kinetic model that can provide a theoretical basis for developing a new mathematical model of the Cr(VI) biosorption column using brown seaweed Ecklonia biomass, a differential reactor system was used in this study. Based on the fact that the removal process followed a redox reaction between Cr(VI) and the biomass, with no dispersion effect in the differential reactor, a new mathematical model was proposed to describe the removal of Cr(VI) from a liquid stream passing through the differential reactor. The reduction model of Cr(VI) by the differential reactor was zero order with respect to influent Cr(IlI) concentration, and first order with respect to both the biomass and influent Cr(VI) concentrations. The developed model described well the dynamics of Cr(VI) in the effluent. In conclusion, the developed model may be used for the design and performance prediction of the biosorption column process for Cr(VI) detoxification.

• International Journal of Advanced Culture Technology
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• 제6권2호
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• pp.129-136
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• 2018

Our present study, we impregnated Al-Fe-Mg-Si (NFM) nanocomposites having various concentrations 0, 1000, 3000, and 5000 mg/L in biomass in order to make carbonized biomass. We characterized the properties of the impregnated samples through thermogravimetric/differential thermal analysis (TG-DTA), pore distribution, scanning electron microscopy (SEM). The best results were observed for a NFM nanocomposites concentration of 5000 mg/L. After the first heat treatment, carbonization, and activation processes, the fixed carbon ratio and iodine adsorptivity were increased by 21.89% and 368 mg/g, 23.98% and 475 mg/g, 26.40% and 238 mg/g, respectively. The remove rate of malodorous and VOCs were that the sample shows good removal capabilities. From above results, our sample could be used for the removal of noxious and malodorous gases and for the purification of wastewater.

• Journal of Microbiology and Biotechnology
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• 제23권1호
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• pp.92-98
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• 2013

Microalgal cultivation using wastewater is now regarded as essential for biodiesel production, as two goals can be achieved simultaneously; that is, nutrient removal efficiency and biomass production. Therefore, this study examined the effects of carbon sources, the N:P ratio, and the hydraulic retention time (HRT) to identify the optimal conditions for nutrient removal efficiency and biomass production. The effluent from a 2nd lagoon was used to cultivate microalgae. Whereas the algal species diversity and lipid content increased with a longer HRT, the algal biomass productivity decreased. Different carbon sources also affected the algal species composition. Diatoms were dominant with an increased pH when bicarbonate was supplied. However, 2% $CO_2$ gas led to a lower pH and the dominance of filamentous green algae with a much lower biomass productivity. Among the experiments, the highest chlorophyll-a concentration and lipid productivity were obtained with the addition of phosphate up to 0.5 mg/l P, since phosphorus was in short supply compared with nitrogen. The N and P removal efficiencies were also higher with a balanced N:P ratio, based on the addition of phosphate. Thus, optimizing the N:P ratio for the dominant algae could be critical in attaining higher algal growth, lipid productivity, and nutrient removal efficiency.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권1호
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• pp.46-56
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• 2013

Laboratory scale experiments to remove benzene in solution by using the bio-carrier composed of dead biomass have been performed. The immobilized bio-carrier with dead Bacillus drentensis sp. and polysulfone was manufactured as the biosorbent. Batch sorption experiments were performed with bio-carriers having various quantities of biomass and then, their removal efficiencies and uptake capacities were calculated. From results of batch experiments, 98.0% of the initial benzene (1 mg/L) in 1 liter of solution was removed by using 40 g of immobilized bio-carrier containing 5% biomass within 1 hour and the biosorption reaction reached in equilibrium within 2 hours. Benzene removal efficiency slightly increased (99.0 to $99.4%{\pm}0.05$) as the temperature increased from 15 to $35^{\circ}C$, suggesting that the temperature rarely affects on the removal efficiency of the bio-carrier. The removal efficiency changed under the different initial benzene concentration in solution and benzene removal efficiency of the bio-carrier increased with the increase of the initial benzene concentration (0.001 to 10 mg/L). More than 99.0% of benzene was removed from solution when the initial benzene concentration ranged from 1 to 10 mg/L. From results of fitting process for batch experimental data to Langmuir and Freundlich isotherms, the removal isotherms of benzene were more well fitted to Freundlich model ($r^2$=0.9242) rather than Langmuir model ($r^2$=0.7453). From the column experiment, the benzene removal efficiency maintained over 99.0% until 420 pore volumes of benzene solution (initial benzene concentration: 1 mg/L) were injected in the column packed with bio-carriers, investigating that the immobilized carrier containing Bacillus drentensis sp. and polysulfone is the outstanding biosorbent to remove benzene in solution.